This invention relates to electronic sensing and actuator control systems for responding to the proximity of an object in a sensing area and for remotely controlling an actuator. The apparatus can be employed as an instrusion detection system during a second mode of operation to protect a secured premise from unauthorized intrusions.
There are a plethora of patents in existence which described electronic locks and keys of all designs and configurations. Many such systems employ a credit card or similarly designed key which may include passive or active circuits for insertion of the same into a slot associated with a lock module. If the apparatus on the card interfaces accordingly with those components present in the lock module, an actuator is energized to enable one to access the area secured by the lock. Such electronic devices have utility in that the locking combinations can be easily changed for use in motel, hotel or similar types of establishments.
Another class of such devices do not require an alteration of an area to create a slot or a key receiving station and operate without such a slot.
Such a system is generally described in U.S. Pat. No. 3,732,465 entitled ELECTRONIC SENSING AND ACTUATOR SYSTEMS by R. S. Polimer and issued on May 8, 1973. Other related systems are shown in U.S. Pat. Nos. 3,752,960, 3,816,708 and 3,816,709.
These systems operate without the need of a card or key accommodating slot and therefore, do not require any modifications to be made to a door or entrance to be accessed and secured by a remote lock according to this type of apparatus.
The systems employ a module which is positioned on a door and which transmits an electrical signal. A card is held in proximity to the door and affects or loads on an oscillator associated with the transmitter. The card contains interconnected electronic components and serves to alter the transmitted signal in a predetermined manner to electrically actuate the locking mechanism.
The advantage of such systems is that one need not access a slot or fit the card or key into an aperture and one merely has to present the card within a sensing area to remotely activate the mechanism.
In any event, such systems suffer in that the cards or keys are relatively complicated and difficult to fabricate as including passive and/or active components. The concept of loading an oscillator is relatively unreliable in that many extraneous noise sources and factors will obscure and effect system operation.
It is therefore an object of the present invention to provide an improved remote actuating and sensing system in the form of an electronic lock, which system can also operate in a second mode to detect the presence of an intruder on secured premises; if desired.